Gravid Uterus.] ANATOM Y. 643 
jure to the future mother, nor without a peculiar fort of 
o-rateful fenfation of the,,internal parts, which become 
thereby highly irritated or convulfed, in a degree threat- 
enin°' to induce a fwoon. From this moment conception 
may^be laid to take place, and tire outlines of a new ani¬ 
mal begin to be evolved by the gravid uterus. 
Dr. Hunter having made an elegant Diffe6lion of the 
Pelvis, and Female Paris, we have annexed a faithful re- 
prefentatiort of the fame, in Plate I. of the Gravid 
\Jteru s, of which the following is an explanation :—A, 
The mons veneris. BB, The feClion of the (kin and adi- 
pofe fubftance, which was thrown open to iliew the pelvis. 
C, The cartilaginous furface of the facrum, by which it 
was joined to the os ilium. DD, The os pubis, cut thro’ 
near the fymphylis. E, Tire external mufcles, on the 
back-part of the pelvis, cut through. F, The mufcles 
which lie on the outfide of the os pubis, cut through. 
G The crus clitoridis, where it was fixed to the ifehium, 
which is removed. II, The fphinuSter vagin’as. I, The 
tfanfverfe mufcleof the perimeum. K, The fpinCterani. 
I,, The bladder, almoft empty, comprelfed between the 
anterior part of the womb and the upper lide of the va- 
eina. M, The levator ani and coccygeusmufcles, by dif- 
ieetion turned down from the contents of the pelvis over 
the cut furface. N, The whole fubftanee of the vagina, 
cut from the neck of the womb and bladder, and turned 
down over the reftum, to (hew the orifice of the womb. 
O, The anterior l ; p of the orifice. P, The pofterior lip 
of the fame. When the vagina was thus opened, the la¬ 
teral fupport being removed, the os uteri puihed out ex¬ 
actly as reprefented in the plate. 
What we have nitherto advanced, coming under the 
teftimony of our fenfes, may be either, confirmed or cor¬ 
rected. " What follows is rather conjeflural; and its deve- 
lopement is the more difficult, as we have few experiments 
to determine the faffs, and even thofe experiments we 
have are diferepant with one another. At the firft outfet 
a difficult quefticn immediately prefents itfelf. Whence 
proceed the firft (lamina of the animal? Are they from 
each parent, and is the new animal formed by a junction of 
the feeds ? The fimilarity of the offspring to both parents 
teems to confirm the opinion. If analogical reafoning 
’ might be permitted, we might adduce numerous examples 
from the vegetable kingdom which clearly fhew that the 
Offspring is a compound of each parent. The opinion is 
ftill farther confirmed by morbid and vicious habits being 
conveyed from both parents to their children. Or, the 
other hand, we have no certain proof that feed exifls in 
the female; and again, animals may be propagated with¬ 
out any mixture of feeds. Laftly, the refemblance of the 
young animal to its hither feems only to (hew, that in the 
male feed there is fome power, which alone can form the 
foft matter of the little embryo; in like manner this fame 
power, in peculiar animals, lengthens the pelvis, dilates 
the thorax, expands the horns, &c. 
Some anatomifts have attributed every thing to the fa¬ 
ther, efpecially after the noted animalcula fyftem came 
under the microfcope, whofe figure perfeTly agreed with 
that of the embryo in all animals. But then there is 
wanting a proportion between thefe animals and the num¬ 
ber of fetufes produced. Another objection to this doc¬ 
trine is, that in moft of the animal tribes animalcula are 
not to be found. And laftly, there is too great a fimilarity 
between thefe animalcula and thofe commonly found in 
other fluids, which always preferve their own peculiar 
fhape, and are never obferved to be changed by growth 
from a Ample worm into a handfome articulated animal, 
wholly diffimilar from themfelves. Other anatomifts, not 
lefs celebrated or lefs worthy of credit, have taught that 
the foetus exifted in the mother and maternal ovary ; 
which the male femen might enliven and varioufly modi¬ 
fy, fo that, at length, it might be brought into the world 
a perfect animal. Certainly the male muft give fome ad¬ 
dition to that fex which produces the fetus from its own 
body ; which addition is neceffary in fome tribes of ani¬ 
mals, but in others, even the moft fruitful, ma^ be want¬ 
ing. This, however, concerns only the materials: but 
we are as much at a iofs concerning the formation ; name¬ 
ly, by what means the rude and fhapelefs mafsof the firft 
embryo is faftiioned into the beautiful diape of the human 
bpdy. We readily rejeft fuch caufes as a fortuitous Con- 
courfe of atoms, the blind attractions between the parti¬ 
cles of the nutritious juices, and the ftrength of ferments, 
not knowing the reafons how they operate; the foul is 
certainly an architect unequal to the ta(k of producing 
fuch a beautiful fabric; and, as we can never fohn any 
adequate ideas of the internal models, we diall refer them 
to thofe hypothefes, which the defire of explaining what 
we ardently widi to know has produced. Experience in¬ 
deed feems to agree with the following deductions which 
reafoning affords, namely, that this moil beautiful frame 
of animals is fo various, and fo exquifitely fitted for its 
proper and diftinCt functions of every kind, and the offi¬ 
ces and manner of life for which the animal is defigned ; 
that it muft be calculated according to laws more perfeCt 
.than any human geometry; that the ends have been fore- 
feen in the eye, in the ear, and the hand ; fo that to thefe 
ends every thing is moft evidently accommodated: it ap¬ 
pears-, therefore, certain, that no caufe can be ailigned for 
it below the infinite wifdom of the Creator himfdlf. 
Again, the more frequently, or the more minutely, we 
■obferve the long feries of increafe through which the 
: (hap clefs embryo is brought to the perfection neceffary for- 
animal lire, fo much the more certainly does it appear, 
_ that thofe parts which are obferved in the more perfect 
fetus, have been prefent in the tender embryo, although 
their (ituation, figure, and compafition, feem at firft to 
have been exceedingly different from what they are at laft j 
for. an unwearied and laborious patience has difeovered 
the intermediate degrees by which the fituation, figure, 
and fymmetry, are infenfibly formed. Even the tranfpa- 
rency of the primary fetus alone conceals many thingswhich 
the colour afterwards added does not generate, but only 
renders- confpicuouS to the eye. And it fuffiiciently ap¬ 
pears that thofe parts which eminent anatomifts have flip- 
pofed to be afterwards- generated, and to be added to the 
primeval ones, have been all contemporary with the prime¬ 
val parts, but only final!., foft, and colyurlefs. It is high-/ 
ly probable, that for a long time the latent embryo nei¬ 
ther increafes, nor is agitated, except by a very gentle 
motion of the humours, which we may fuppofe to librate' 
from the heart into the neighbouring arteries, and from 
thefe into the heart of the fetus. But wc may alfo fup¬ 
pofe, that the fumulus of the male femen excites the heart 
of the fetus to greater contractions, fo that it infenfibly 
evolves the complicated veffels of the reft of the body by 
the impulfe of the humours, and propagates the vital mo¬ 
tion through all the canals of the little body of the ani¬ 
mal, quicker in fome parts, and flower in others; and 
that thence fome parts feem to be produced very early, 
others to fupervene afterwards; and laftly, fome do not ap¬ 
pear until a long time after birth, as the veficles of the 
ovaries, the velfels of the male tefticles, the teeth, hairs 
of the beard, and horns of brute animals. In all animals, 
heat aflifts this evolution; in the more (imple ones, whofe 
veffels are few, and lefs complicated in their* various or¬ 
gans, heat is the foie inllrument of bringing it to perfection* 
After the human ovum is brought down into the uterus, 
we become fenlible of its change of fhape in a few days. 
The ovum itfelf fends out every where foft branchy floc-- 
culi from the fuperficies of its membrane hitherto fmooth, 
which adhere to, and inofculate with, the exhaling and 
reforbing flocculi of the uterus,. This adhefion happens 
every where in the, uterus ; but chiefly in that thick part 
which is interpofed between the tubes, and is called the 
fundus uteri. Thus the thin ferous humour of the uterus, 
proceeding, from its arterial villi, is received into the (len¬ 
der venous veffels of the ovum, and nourifhes it together 
with the. fetus. Before this adhefion, if at any time it 
does not adhere^ it is. nouri (lied either by its own or by 
abforfceff 
